The present invention relates to a utility knife, and more particularly, to a utility knife with a slide fabricated of a material into which the blade will cut.
Utility knives are well known and used for a wide variety of tasks because of their replaceable razor-like blades. The bulk of the utility knives have a slide element upon which the blade is supported for movement into and outwardly of the casing or handle.
In recent years, some utility knives have been fabricated from synthetic resin because molding of resin enables precision fabrication at low cost. Other slides have been fabricated of die cast zinc and aluminum for the same reason. However, a slide made of synthetic resin or a relatively soft metal is prone to being cut into or sheared by the blade so that harder metal slides have been preferred. Use of low friction resins such as polyamides and polyacetals provide low friction slides but have a tendency to shear at their base wall having the blade edge bearing thereon. A similar problem exists with respect to slides formed from softer metals.
A number of prior art devices have sought to restrict unwanted inward movement and upward rotation of the rear or inner end of the blade relative to the slide by means of a stop on the slide against which the inner end of the blade abuts. However, none of these devices has sought to translate the forces causing the unwanted cutting or shearing of the slide to non-destructive forces.
It is an object of the present invention to provide a utility knife with a novel slide which reduces the unwanted tendency of the blade to cut into or shear the slide.
It is also an object to provide such a utility knife in which the slide is configured to resist rotational forces acting upon the blade.
It is a further object to provide such a utility knife which may be fabricated readily and economically and readily assembled to provide relatively long-lived operation.